A fingerprint detection apparatus collects fingerprint information through a collection module and generates a fingerprint detection signal, then processes the fingerprint detection signal through a processing module to generate and output fingerprint image data, and conducts matching identification on the data outputted. A capacitive fingerprint detection apparatus has been gradually applied to a handheld apparatus (for example, a mobile phone, a tablet, etc), while the application environment is complicated and versatile due to the portability of the handheld apparatus, so that the fingerprint detection apparatus also needs to cope with various application environments.
From the aspect of measuring signals, the direct influence brought by the change of the application environment is namely noises, while a noise signal will influence the signal to noise ratio of the fingerprint detection signal, and reduce the anti-interference capacity. The inventor finds through careful studies that in a usual case, the frequency spectrums of the noise signal are distributed widely, while the frequency spectrums of the fingerprint detection signal are relatively narrow. If the bandwidth of the fingerprint detection signal can be reduced, the signal to noise ratio can be improved accordingly, so as to increase the anti-interference capacity of the fingerprint detection apparatus.